Re: [time-nuts] Freq cal to 1ppm without GPSDO
Thanks to you and the others for your replies. After some more HF reception problems here, I have come to the same conclusion as you. I found an Oncore M12+ timing GPS is available pretty cheap from Hong Kong, so that's my plan. Years ago, I remember smiling when I figured out that I could calibrate the clock in a scope. Just trigger on a PPS signal, dial out the delay to about 1 second, then see where the next PPS signal actually is. (The scope was off about 6 ppm.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Freq cal to 1ppm without GPSDO
John, Besides the M12 receiver you will need an interface board to provide a 3.3 volt regulator for the M12, a 5 volt regulator and some 74c04's or some such to provide the 1pps interface and drive levels to a MAX232 chip for a RS232 interface. Then you will need to build up the Brooke Shera comparator and control board to interface a high quality oscillator in order to duplicate what is already provided in the Trimble Thunderbolt GPSDO. The Brooke Shera system gives you a part by part insight on what goes on in the Thunderbolt. However, there is a bit of work to get the Shera system up and running. The advantage of the Thunderbolt is that it is pretty much a plug-n-play unit. 73BillWB6BNQ John Beale wrote: Hi Murray, Thanks to you and the others for your replies. After some more HF reception problems here, I have come to the same conclusion as you. I found an Oncore M12+ timing GPS is available pretty cheap from Hong Kong, so that's my plan. best regards, John Beale 1. My best advice is to get hold of a cheap GPS module with a 1pps (seconds pulse) output. Connect it up, and when you have a fix, use the 1pps to trigger your digital oscilloscope. Set the timebase to 1us/div to start with, and ultimately 100ns, and observe the 10MHz output of your TCXO. You will see the waveform drifting slowly. Counting how long it takes to slip one cycle will tell you how far off the TCXO is. If you have a counter with Time Interval mode capability, you could use that, using the GPS to start and 10MHz to stop, again observing the drift. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Freq cal to 1ppm without GPSDO
John, One other thing I forgot to touch on. The 1pps signal out of the a GPS receiver is very jittery. For your TCXO it will be good enough except for you having to stare at the scope while comparing the GPS to your TCXO. Any oscillator of higher quality will be a problem when just using the GPS in the raw manner you are suggesting. 73BillWB6BNQ John Beale wrote: Hi Murray, Thanks to you and the others for your replies. After some more HF reception problems here, I have come to the same conclusion as you. I found an Oncore M12+ timing GPS is available pretty cheap from Hong Kong, so that's my plan. best regards, John Beale 1. My best advice is to get hold of a cheap GPS module with a 1pps (seconds pulse) output. Connect it up, and when you have a fix, use the 1pps to trigger your digital oscilloscope. Set the timebase to 1us/div to start with, and ultimately 100ns, and observe the 10MHz output of your TCXO. You will see the waveform drifting slowly. Counting how long it takes to slip one cycle will tell you how far off the TCXO is. If you have a counter with Time Interval mode capability, you could use that, using the GPS to start and 10MHz to stop, again observing the drift. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Supply - Final word
Fleming was perfectly located, in spite of himself, the problem of all groups and clubs in the world. There is always an imbalance between theory, practical experience and implementation. There are always good advice, but hardly any solutions. I invite us all to use most of the iron to finish the process that starts from the theory, design and ending with implementation. Otherwise we run the risk to celebrate itself without producing anything of working. Luciano Luciano P. S. Paramithiotti -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Flemming Larsen Sent: giovedì 17 febbraio 2011 3.19 To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Thunderbolt Supply - Final word Didier et al, I did not ask for, and did not expect rocket science. Just a simple solution or advice from some of the much more experienced people on this list. I am trying to put my equipment together after having had everything in storage for several years. Being retired and on a limited budget, I am trying to make what I have work, rather than trying to reinvent the wheel. Given enough time and an unlimited budget, I'm sure that I could come up with a better solution. For the time being, I was hoping that someone on the list could point me to a simple solution that would fit my needs and budget, thinking that lots of other people have had to go through similar steps with the number of Chinese switching power supplies that were sold with the Thunderbolts, both here on the list and on eBay. just care and good engineering. I totally agree. I did that professionally for many years, but now I'm retired and no longer have access to the resources and test equipment I used to have access to at work. Other people on the list have access to better resources than I do and many people have more experience than I do, especially when it comes to switching power supplies. I appreciate all the advice I was given, although nobody pointed me to a circuit with component values that I could simply duplicate, instead of having to go the whole process of getting my books off the shelf and do what others have already done. No matter now. UPS just brought me a nice linear power supply today. 5 volts @ 28 amps and +/-12 volts @ 3 amps. Although probably many times overkill for the application and as big as breadbox, this should probably work, and without the unnecessary need to add complex (or not) filters. Thanks again, -- Flemming LarsenOZ6OI/KB6ADSBerkeley, CA, USA Sent from my computer Sent from my Verizon Wireless BlackBerry ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] advice: frequency calibration to 1 ppm possible without GPSDO?
On 02/17/2011 01:58 AM, beale wrote: Hello time enthusiasts! I'm hoping for your advice on my (perhaps modest, by this list's standards) project. I would like to make a frequency calibration of a 10 MHz oscillator to 1 ppm (1E-6) or better, using some basic equipment. I do not have a GPSDO or any serious lab equipment, or budget for same as this is just a personal project. What I do have access to: I did a piece of software to provide calibration to equipment-deficient microcontroller-hobbyist frequency counter builders (think 100ppm crystal from the bin) over ntp: http://n1.taur.dk/nft/nft.pdf (usage guide with relevant screenshots, required reading) http://n1.taur.dk/nft/nft.exe http://n1.taur.dk/nft/nftsrc.zip (delphi source) Depending on how you are connected, 0.1ppm is quite doable. Measure, adjust, measure 3 times to verify. When you decide that this is too cumbersome and buy a GPS with pps output, you could make it self-adjusting: http://n1.taur.dk/simplexdo/ /Kasper Pedersen ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts!
David Taylor wrote: Have you heard anything from Garmin? I take it you have reported the issue. I have only received an automated reply from the Garmin site so far David: Category Or Device: GPS 18 Serial Problem Description: I measured the START and END time (to nearest millisecond) of the RMC NMEA sentence, with respect the 1PPS pulse. From version 3.3 to 3.6 the NMEA has been retarded more and more. With V3.6 of the 18x firmware, the RMC sentence at default 4800 finishes in the NEXT second. So if the 18x is used to give accurate time - it is 1 second SLOW. This does NOT happen on version 3.2 of the 18x firmware. Regards, Geoff (NZ). ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. However, I agree about the high price. That would be better than go away Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: li...@lazygranch.com Sender: time-nuts-boun...@febo.com Date: Wed, 16 Feb 2011 20:37:38 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: li...@lazygranch.com, Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem If you want to write a turd note about their service, I will pin it on their door. These companies need to know the reach of the internet. If they had any brains, they would offer you a replacement at a ridiculously high price. -Original Message- From: Brendan Minish ei6iz.bren...@gmail.com Sender: time-nuts-boun...@febo.com Date: Wed, 16 Feb 2011 20:11:37 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem Right, to follow up on my own email I took it apart The lamp assembly has failed. In the PRS10 the lamp is exited by a strong RF field @ 150Mhz this is generated by an MRF134 within the lamp package The failure mode was caused by the growth of a substantial tin whisker within the lamp assembly which appears to have killed the MRF134. I made contact with SRS about purchasing a replacement lamp assembly but since I bought it on the used market they are not willing sell me a replacement lamp assembly. Frankly I am not terribly impressed with their response on this. Does anyone on list have a 'donor' PRS10 that might have a good lamp assembly that they would be willing to sell me ? Perhaps someone on list has a commercial relationship with SRS and might be able to assist me with purchasing it? Hoping someone can help out, My alternative is to attempt to source an MRF134 and have a go at replacing it but there may be other damage in there regards Brendan On 14/02/2011 18:53, Brendan Minish wrote: Hello all My SRS PRS10 ( http://www.thinksrs.com/products/PRS10.htm ) Rubidum frequency standard was power cycled a few days ago, since then it has not achived rubidium lock. I have tried a full rest and also further power cycles with no joy. The SRS RS232 application reports the following parameters that 'look wrong' ad3 (lamp drain ) 2.001 sd2 (fet voltage set ) 255 ad3 at 2 (Lamp drain volatge 20V) would appear to correspond with the Rb lamp discharge not beginning this unit is of course out of guarantee and came to me via Ebay about 5 years ago, is anyone on list familiar with troubleshooting these units who Might have some general ideas of how best to proceed with repairing the unit -- 73 Brendan EI6IZ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts!
David Taylor wrote: Have you heard anything from Garmin? I take it you have reported the issue. I have only received an automated reply from the Garmin site so far David: [] Regards, Geoff (NZ). In the absence of a further reply, may I suggest that you report the problem directly to your local Garmin rep? I found: _ Garmin Australasia Unit 19 167 Prospect Highway Seven Hills, NSW 2147 Australia Customer Support: 1800 235 822 Australia Fax Number: 02 8882 6150 New Zealand Customer Support: 0800 427 652 New Zealand Fax Number: 0800 427 646 _ Cheers, David -- SatSignal software - quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
Or you try all the possible solutions all at once in parallel in a big FPGA and you have instant synch (at least in the time it takes to recognize you have it) May be impractical for very long, complex sequences... Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: jimlux jim...@earthlink.net Sender: time-nuts-boun...@febo.com Date: Wed, 16 Feb 2011 21:26:01 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] PN sequence generation using GPS On 2/16/11 5:04 PM, Joe Leikhim wrote: Thanks Bob; Does this mean that the 10 MHz clock needs to be somehow divided to an integer evenly divisible by 127 seconds? Also 8192 seems to be unfeasible as it would take 2.2 hours to initialize sync. No.. your 1pps/sync loads the register with all ones... that's what the sync is. If you want to synchronize without help, what you do is slide the receiver steadily by the transmitter, slipping one chip at a time (or offsetting the frequency slightly). The challenge is that you need to be close enough as you slide by for long enough to recognize that you've got sync. Say you've got a 1023 long code (a 10 bit generator) running at 1 MHz. Say it takes 1 millisecond to tell if you are in sync. You can try all 1023 possible relative phases in 1 second, roughly, and the average time will be a half second. You can do this try all phases by running one clock 1ppm slow, relative to the other, or you can run them at the same speed, and drop a pulse every code period. Depends on if you have a digital or analog implementation.. For a digital implementation, it's often convenient to detect when the generator register is all ones, which occurs only once a code period. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
Hi The key item here is that the system is going to work via amateur radio here in the US. The FCC only lets you use three very specific PN sequences. The three are called out explicitly in the rules. The requirement that they not be reset while transmitting except by feedback is also called out explicitly in the rules. So no fancy stuff with multiple spreaders and the like. The fact that they work out to primes is not important other than there's not much use trying to factor them. Without any common factors, and with 1 pps as your reset, you get a pretty specific trigger point for reset. It's long enough to not be of much use. There's a much easier way to do it and keep everybody in sync. GPS gives you time of day along with the 1 pps signal. You agree that at this or that time, everybody starts in sync. It's just time math to figure out where you should be at any 1 pps point. If you aren't where you are supposed to be, you take action. I suspect you could do all the checking on a 50 cent processor. Latch the data at 1 pps and read the time string. Do the math to check it. Fire the alarm flag it's not right. Not a lot to get done in a second. Bob On Feb 16, 2011, at 7:22 PM, Magnus Danielson wrote: Bob, On 02/16/2011 10:51 PM, Bob Camp wrote: Hi According to the rules, you are not allowed to reset shift register other than by feedback during a transmission. In order for a reset to be transparent it would have to always happen at the same time. Usually that's when the register is full or empty. A proper (MLS) PN sequence will be (2^m) -1 long. For the allowed ham sequences that would be 2^7 -1 = 127, 2^13 -1 = 8191, or 2^19 -1 = 524287. If they are not MLS then I'm off a bit. None of those divide into 10 MHz very well at all, since they all are prime numbers. It's actually not the prime-number aspects which is important, all Maximum Length Sequences (MLS) will not be prime-number lengths as not all Mersenne numbers is primes, and then non-prime polynomial lengths like 10 naturally breaks up (1023 = 31*33). The key factor is that the sequences does not line due to lack of common factors. However, this deficiency can be overcome by shortening the sequence. If you use the shortest sequence, you would get to reset every 127 seconds with a simple approach. You likely would do better to run a bit more math and figure out the right sequence for the time you are at. Probably more trouble than it is worth it. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On 02/17/2011 12:42 PM, shali...@gmail.com wrote: Or you try all the possible solutions all at once in parallel in a big FPGA and you have instant synch (at least in the time it takes to recognize you have it) May be impractical for very long, complex sequences... Modern quick-lock approaches uses FFT. Very effective form of cross-correlation operation. Works like a charm for GPS for instance. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
A while ago, I took a pair of watches (a Bulova and a Seiko) that needed new batteries to a fancy jewelry store here in town (VanDeGriff) because I thought they would do a good job. The Bulova took 6 weeks... (They apparently did not service anything locally and had to sent it out). They said they had to replace the movement, which I did not know needed replacement. I asked them to return the bad movement with the watch, but I never got it. They broke the crystal on the Seiko and replaced it with a different one, which I made them replace again (good thing that I took very sharp digital pictures of the watches before I turned them over to the store). They did not charge me for the crystal on the Seiko (they broke it), but that one took 3 months and cost $25 ($10 for the battery and $15 for shipping both ways to the repair shop). I paid well over $100 for the Bulova. Since then, I bought a set of tools to safely open the back of most of my watches. For those I do not want to do myself, I take them to a small shop in the local mall that replaces the battery while you wait and you can see the guy while he does it. I have not had problem with him whatsoever, and he charges $7. He does not do pressure checks. I have returned watches directly to Seiko in the US (Coserv) for movement or crystal replacement. A new movement costs about $90 and a crystal costs about $15. They do a good job (as far as doing what you ask them to do), but they apparently do not routinely replace the o-ring or do pressure check because the watches I got back from them all took moisture... Next time I send one, I will specifically ask for new o-rings and pressure check. I have also returned a Citizen to Citizen US because the number 12 had come unglued from the face. They also did an excellent job for little money. YMMV Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Chris Albertson albertson.ch...@gmail.com Sender: time-nuts-boun...@febo.com Date: Tue, 15 Feb 2011 11:53:27 To: Discussion of precise time and frequency measurementtime-nuts@febo.com; W1LEstanw...@verizon.net Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Tool Needed to Access my Timer Battery Almost any place that sells quality watches will replace the battery for you for about the price of the battery. It takes about 5 minutes and they will have the tools and battery You should get most of your $10 bill back as change Typically there are two types of rear covers some are threaded and others use a snap/friction fit. Battery and o-rings are not designed special for each model of watch and are standard parts -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Supply - Final word
Precisely because most of us do not have access to much fancy test equipment (I am one of the lucky ones), there is no excuse for not using freely available, quality tools (assuming that you have a computer) like LT Spice. Of course, you have to be careful as the quality of the output from any simulation software will only be as good as the inputs you feed into it. However, used appropriately, it will save you hours on the bench, and avoid the pain and embarrassment of building something that may have a major flaw. Also, it allows you to verify that your circuit will work under conditions that may be difficult to experimentally create (such as aging, component tolerances and temperature). So when Bruce offers his advice based on Spice simulations, I pay attention. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Paramithiotti, Luciano Paolo S luciano.paramithio...@hp.com Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 08:37:24 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Thunderbolt Supply - Final word Fleming was perfectly located, in spite of himself, the problem of all groups and clubs in the world. There is always an imbalance between theory, practical experience and implementation. There are always good advice, but hardly any solutions. I invite us all to use most of the iron to finish the process that starts from the theory, design and ending with implementation. Otherwise we run the risk to celebrate itself without producing anything of working. Luciano Luciano P. S. Paramithiotti -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Flemming Larsen Sent: giovedì 17 febbraio 2011 3.19 To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Thunderbolt Supply - Final word Didier et al, I did not ask for, and did not expect rocket science. Just a simple solution or advice from some of the much more experienced people on this list. I am trying to put my equipment together after having had everything in storage for several years. Being retired and on a limited budget, I am trying to make what I have work, rather than trying to reinvent the wheel. Given enough time and an unlimited budget, I'm sure that I could come up with a better solution. For the time being, I was hoping that someone on the list could point me to a simple solution that would fit my needs and budget, thinking that lots of other people have had to go through similar steps with the number of Chinese switching power supplies that were sold with the Thunderbolts, both here on the list and on eBay. just care and good engineering. I totally agree. I did that professionally for many years, but now I'm retired and no longer have access to the resources and test equipment I used to have access to at work. Other people on the list have access to better resources than I do and many people have more experience than I do, especially when it comes to switching power supplies. I appreciate all the advice I was given, although nobody pointed me to a circuit with component values that I could simply duplicate, instead of having to go the whole process of getting my books off the shelf and do what others have already done. No matter now. UPS just brought me a nice linear power supply today. 5 volts @ 28 amps and +/-12 volts @ 3 amps. Although probably many times overkill for the application and as big as breadbox, this should probably work, and without the unnecessary need to add complex (or not) filters. Thanks again, -- Flemming LarsenOZ6OI/KB6ADSBerkeley, CA, USA Sent from my computer Sent from my Verizon Wireless BlackBerry ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] NATIONAL RADIO NC-2001,2011 CESIUM BEAM MANUAL
Wow this is a real time-nuts C standard. It has all the Right Stuff. Power, heat, and weight and if I had to guess the smell of baking phenolic and such. Someone would actually believe this is a standard. Not the modern day wimpy things we use that you can lift with 1 or 2 hands. Heck its VCO is servo motor tuned so it even makes noise. The oven, the size of a toaster. At least for me a great read later today. Its funny even though I knew there were things before the HP5061. I had never really run across any real information in detail. This does. Thanks John and Dave for making this available to the time-nuts for a small cost. Regards Paul WB8TSL On Wed, Feb 16, 2011 at 9:50 PM, paul swed paulsw...@gmail.com wrote: Just sent Dave a paypal request. On Wed, Feb 16, 2011 at 7:48 PM, paul swed paulsw...@gmail.com wrote: Yup think I will order a download tomorrow from Dave. Looks like real time nuts equipment. Power, heat, and weight. What more could you ask for. Oh the ability to actually see the components I will bet. But I bet this would be quite a read as manuals go. Thanks John Regards Paul. On Wed, Feb 16, 2011 at 5:36 PM, Pete Lancashire p...@petelancashire.com wrote: Before my fire, I had the 5 or 6 volume 'manual' for the B-24 bomber. A good 2/3rds of the drawings and almost all the foldouts where colour. Def will order one of these from Dave. -pete On Wed, Feb 16, 2011 at 2:25 PM, John Miles jmi...@pop.net wrote: This turns out to be a really neat document. It has foldouts that I couldn't scan in one piece with the equipment I have, so I sent it to Dave at Artek Media. He's done a stalwart job of scanning the manual at high resolution with as much of its original patina as could be retained without going completely out of control with the file size. As it is, it's over 100 MB, due to being scanned in color at my request. Sounds pointless for a service manual, but the reason is apparent as soon as you open the file, because this isn't just another service manual. Here's his listing for the scan: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=390289796187 A couple of sample pages: http://www.thegleam.com/ke5fx/sample1.jpg http://www.thegleam.com/ke5fx/sample2.jpg Recommended for Cs clock nuts and history-of-technology fans in general. (The original is spoken for.) -- john, KE5FX -Original Message- From: John Miles [mailto:jmi...@pop.net] Sent: Tuesday, January 25, 2011 11:46 AM To: Discussion of precise time and frequency measurement Subject: RE: [time-nuts] NATIONAL RADIO NC-2001,2011 CESIUM BEAM MANUAL C'est moi. I wanted a chance to scan it before it's lost forever in the tubes. I'll relist it as soon as I'm done (or someone can just buy it from me for the same price.) Would be nice if the original eventually finds a home with an NC-2001 or -2010. The manual would probably be of some interest to an NC-1001 owner as well, since it would give an idea of the improvements made in the next version. Not sure what differences exist but I'll bet they have a lot in common. A catalog of documents held by the Smithsonian ( http://sirismm.si.edu/archivcenter/findingaids/AC0547.pdf ) suggests that the NC-2001 was a 'militarized' version from the same basic era as the NC-1001. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com ]On Behalf Of Scott Newell Sent: Tuesday, January 25, 2011 10:19 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] NATIONAL RADIO NC-2001,2011 CESIUM BEAM MANUAL At 11:24 AM 1/25/2011, Scott Newell wrote: At 11:14 AM 1/25/2011, Bob Camp wrote: Looks like somebody grabbed it pretty fast. I wonder if they have the hardware that goes with the manual? I sent the ebay link to a friend with one, but I've not heard if he bought the book. Oops. I just heard back; my friend has an NC-1001, not the NC-2001. So it wasn't him. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5061B manual wanted
A great way to get that National manual :-). I've sent Dave manuals in the past and have always got them back in the condition I sent them in. Since I have access to a paper knife I've had the spines sheared off before sending. -pete On Wed, Feb 16, 2011 at 9:06 PM, John Miles jmi...@pop.net wrote: Also on the subject of Cs reference service manuals, Artek is looking for a copy of the HP 5061B service manual to scan. If anyone can help, you'll get your original back plus two free manual CDs of your choice. Contact Dave at manuals (at) artekmedia.com if interested. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
I am trying to stay within the FCC Part 97 rules. The spreading or hopping will be of a narrowband (25 KHz BW) FM signal. I haven't decided on either the FHSS or DSSS approach. I had thought of a FH approach that exploited time of day to address a frequency look up table, but I think that is outside Part 97, although arguably it is a net scheduler. 1) If I go with a FH approach running at around 10-20 hops/second will the 1 pps be sufficient? 2) Part 97 says the shift register cannot be reset by anything other than by itself during a transmission. Clearly many of the synchronization methods discussed in the ARRL SS Sourcebook utilize a synch method transmitted across the link or derived from a TV broadcast signal etc. I don't see the reason this rule exists? 3) If I block the 1 PPS during PTT, and the receiving end asserts 1 PPS reset, will synch be lost? If not how effective will the freewheeling be during a 30 second exchange with 10 MHz GPS derived clock reduced to 20 hops/second? 4) 20 hops per second is a 50 ms chip. Two radios 50 miles apart would be 270 us delayed. I don't think that should impair the analog FM. So don't envision needing any correlation adjustment. Comments? From: Bob Camp Hi The key item here is that the system is going to work via amateur radio here in the US. The FCC only lets you use three very specific PN sequences. The three are called out explicitly in the rules. The requirement that they not be reset while transmitting except by feedback is also called out explicitly in the rules. So no fancy stuff with multiple spreaders and the like. The fact that they work out to primes is not important other than there's not much use trying to factor them. Without any common factors, and with 1 pps as your reset, you get a pretty specific trigger point for reset. It's long enough to not be of much use. There's a much easier way to do it and keep everybody in sync. GPS gives you time of day along with the 1 pps signal. You agree that at this or that time, everybody starts in sync. It's just time math to figure out where you should be at any 1 pps point. If you aren't where you are supposed to be, you take action. I suspect you could do all the checking on a 50 cent processor. Latch the data at 1 pps and read the time string. Do the math to check it. Fire the alarm flag it's not right. Not a lot to get done in a second. Bob -- Joe Leikhim Leikhim and Associates Communications Consultants Oviedo, Florida www.Leikhim.com jleik...@leikhim.com 407-982-0446 WWW.LEIKHIM.COM ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Freq cal to 1ppm without GPSDO
On Wed, Feb 16, 2011 at 11:43 PM, David J Taylor david-tay...@blueyonder.co.uk wrote: Would you count these as nearer a working system? Only needs USB power, and includes the antenna and cable. http://www.sureelectronics.net/goods.php?id=99 I'm still waiting for mine to arrive. The advantage of the Oncore GPS is that it is well documented. Motorola wrote some detailed manuals in good English that are on-line. The Sure units are more ready to use but come with typical Chinese eBay documentation. Not saying which to get. Either should work. It's not hard to set up an Oncore GPS, just power it and interface it to RS232. the MAX232 chip makes that part easy and you can find DB9 connectors with the chip attached for about $4. But those Thunderbolt units are selling for $100 and are GPSDXOs with very good specs and only need power and an Antenna For many people the Antenna is that hardest part. You need a clear view of the sky and if it snows at your location some setup that keeps it clear of snow and then you need a cable from the Antenna back to the GPS. Running a wire out an open windows works for a test but not long term, Long tern you'd want a pole mount antenna up on the roof. So a few voltage regulators and interface chips is not much work compared to a permanent antenna setup One thing to look at when choosing a GPS is software. Maybe you are going to run an NTP server or you need software that runs on Linux. Or maybe you plan to buy several GPS receivers and want software that can run all of them. Always the old joke is true: A man who has one GPS knows what time it is, A man with two is never sure. So you buy three. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Freq cal to 1ppm without GPSDO
Hi There is another route to getting where you want to go. Buy an atomic clock. If you spend some time shopping, telcom rubidium atomic clocks are out there for sub $50 prices. For $100 you can get one quite quickly. An Efratom LPRO is one example. There are many others. They normally put out 10 MHz and some put out 1 pps. I'd avoid the 1 pps only versions for what you are trying to do. To be absolutely perfect, you do need to calibrate an Rb. I have never seen one that was off by more than 0.5 ppb (0.0005 ppm). Their tune range is rarely more than a few ppb. More or less - if they fire up and lock, they will do what you need to do. Of course if you have both the GPS *and* the Rb then you can calibrate the Rb against the GPS and get it real close. Welcome to time nuts Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of John Beale Sent: Thursday, February 17, 2011 1:10 AM To: time-nuts@febo.com Subject: Re: [time-nuts] Freq cal to 1ppm without GPSDO Hi Murray, Thanks to you and the others for your replies. After some more HF reception problems here, I have come to the same conclusion as you. I found an Oncore M12+ timing GPS is available pretty cheap from Hong Kong, so that's my plan. best regards, John Beale 1. My best advice is to get hold of a cheap GPS module with a 1pps (seconds pulse) output. Connect it up, and when you have a fix, use the 1pps to trigger your digital oscilloscope. Set the timebase to 1us/div to start with, and ultimately 100ns, and observe the 10MHz output of your TCXO. You will see the waveform drifting slowly. Counting how long it takes to slip one cycle will tell you how far off the TCXO is. If you have a counter with Time Interval mode capability, you could use that, using the GPS to start and 10MHz to stop, again observing the drift. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On 2/17/11 3:42 AM, shali...@gmail.com wrote: Or you try all the possible solutions all at once in parallel in a big FPGA and you have instant synch (at least in the time it takes to recognize you have it) May be impractical for very long, complex sequences... If the sequence is long, then what you do is a FFT based fast cross-correlation.. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On 2/17/11 7:22 AM, Joe Leikhim wrote: I am trying to stay within the FCC Part 97 rules. The spreading or hopping will be of a narrowband (25 KHz BW) FM signal. I haven't decided on either the FHSS or DSSS approach. I had thought of a FH approach that exploited time of day to address a frequency look up table, but I think that is outside Part 97, although arguably it is a net scheduler. 1) If I go with a FH approach running at around 10-20 hops/second will the 1 pps be sufficient? yes...There have been a fair number of FM frequency hoppers over the years with 10-100 Hz hop rates. At 10 Hz, you can be pretty sloppy in your hop timing (if you were off by 1 millisecond, it just looks like a 1ms noise burst at 10Hz... sounds like ignition noise) A common architecture was a Z80 or 6502 driving the PLL divisor bits in the MC145xxx PLL in an off the shelf FM land mobile or CB type radio. 2) Part 97 says the shift register cannot be reset by anything other than by itself during a transmission. Clearly many of the synchronization methods discussed in the ARRL SS Sourcebook utilize a synch method transmitted across the link or derived from a TV broadcast signal etc. I don't see the reason this rule exists? Probably to allow a monitoring organization to not have to work too hard. 3) If I block the 1 PPS during PTT, and the receiving end asserts 1 PPS reset, will synch be lost? If not how effective will the freewheeling be during a 30 second exchange with 10 MHz GPS derived clock reduced to 20 hops/second? Practical experience says that you can use no external reference, and use the oscillator that you're using for the FM carrier. Slow hopping doesn't require fantastically good timing. You can actually use the squelch to resync on each hop. When you hit the PTT, you either can start at a known frequency and restart the sequence (the receiver sits waiting at that home frequency) OR you can run the clock forward as a best guess, and then resync on each hop. 4) 20 hops per second is a 50 ms chip. Two radios 50 miles apart would be 270 us delayed. I don't think that should impair the analog FM. So don't envision needing any correlation adjustment. Comments? Many, many slow hoppers of the 1980s worked exactly like that. Some used digitized voice (CVSD was popular) some were just analog FM. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On 2/17/11 9:30 AM, Bob Camp wrote: Hi System design is always about compromise. If you hop slowly, you stomp on each channel pretty hard. You are likely to get noticed when you do. The idea is to stomp so rarely and for so short a time that you aren't noticed. If you hop fast, you need to adjust the sequence to match. If you have a max distance of 50 miles / 270 us and a 270 us chip rate things are still pretty easy. You only need to be able to adjust over a +/- 1 chip range. More or less like a fine tuning knob. If you are trying this with a conventional radio, there are some other issues. The PLL lock times are way longer than the 270 us you are looking at for distance. Based on using radios as scanners, anything dimensioned in hops/second is likely sound bad. My practical experience has been that the typical ham 2m or 440 rig (or a land mobile rig, which is essentially the same) has a PLL lock time in the 1-few millisecond range, and a hop length of 100 ms works pretty well. The noise blanker helps deal with the popping.. I set up an experiment 20 or so years ago using a pair of FT-757GXs in the 40m band, driving the computer control port with frequency change commands, and it worked fairly well. Didn't radiate (transmit into a dummy load, receive from leakage... the radios were sitting on the same table) Any VHF/UHF rig already flips the PLL frequency when going from tx to Rx to accomodate the IF and/or repeater offset, so you can look at the Rx/Tx turnaround times for packet radio to get a feel for it. If you use digitized voice (say, CVSD at 16 kbps, which is easy and doesn't sound too bad and doesn't have licensing issues) you can buffer it up and transmit at a higher rate (e.g. if you have a dead time of 10 ms out of every 100ms, you transmit at 1.1 times the bit rate you digitized at) One caution... Spread Spectrum communications is something that is desirable by various bad people (because it's moderately secure and also low probability of intercept), and so you might attract attention of people who worry about things like that. You might have a car with small hubcaps and lots of antennas sitting outside your abode one morning, with someone who just has a few questions. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
As an aside to the watch repair business, a large number of brands primarily Swiss, will no longer supply parts to watchmakers. This has become a big issue among the independent watch repairers in the US. It really is an issue of restraint of trade but is currently unresolved. Though not exclusively, the makers refusing to supply parts are the higher end makers. In order to get your Patek Phillipe repaired for example, you must bring it to an authorized Patek dealer who then (usually) will send it to a central repair location. The cost of repair is substantially higher under those circumstances. A list of makers refusing to supply parts to independent repairers can be found here: http://www.ccwatchmaker.com/restrictedbrands.html Bill S ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
hate say it. Time for the $3 timex On Thu, Feb 17, 2011 at 2:21 PM, Bill S w...@jbpet.com wrote: As an aside to the watch repair business, a large number of brands primarily Swiss, will no longer supply parts to watchmakers. This has become a big issue among the independent watch repairers in the US. It really is an issue of restraint of trade but is currently unresolved. Though not exclusively, the makers refusing to supply parts are the higher end makers. In order to get your Patek Phillipe repaired for example, you must bring it to an authorized Patek dealer who then (usually) will send it to a central repair location. The cost of repair is substantially higher under those circumstances. A list of makers refusing to supply parts to independent repairers can be found here: http://www.ccwatchmaker.com/restrictedbrands.html Bill S ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
$12 inflation. -John = hate say it. Time for the $3 timex On Thu, Feb 17, 2011 at 2:21 PM, Bill S w...@jbpet.com wrote: As an aside to the watch repair business, a large number of brands primarily Swiss, will no longer supply parts to watchmakers. This has become a big issue among the independent watch repairers in the US. It really is an issue of restraint of trade but is currently unresolved. Though not exclusively, the makers refusing to supply parts are the higher end makers. In order to get your Patek Phillipe repaired for example, you must bring it to an authorized Patek dealer who then (usually) will send it to a central repair location. The cost of repair is substantially higher under those circumstances. A list of makers refusing to supply parts to independent repairers can be found here: http://www.ccwatchmaker.com/restrictedbrands.html Bill S ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
I wanted to say those customers who bought them new directly from them While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket. What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant. They do not want to exert control on who owns it later, but they exert control on what they do with their spares. Its a fact of life. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 18:26:41 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
I've had such blowoffs from SRS, simply asking for a schematic of an old power supply. Uncooperative and unhelpful is a total understatement. I will never buy any of their stuff again. I simply don't care if it is the best in the world (which it is probably not the case), if the documentation and other minimal support is not available, they are simply a company not worth dealing with. Even if I got it free, it's still not worth half the price. YMMV, -John = I wanted to say those customers who bought them new directly from them While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket. What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant. They do not want to exert control on who owns it later, but they exert control on what they do with their spares. Its a fact of life. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 18:26:41 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
I've worked for Fortune 100 companies (let alone the top 500) and start-ups. They both often buy used gear. Even if the gear breaks and needs repairs, there are accounting reasons why buying used makes sense. (Repairs are expensed. Bean counters like that.) Thus to screw anyone that buys used is a poor business practice. HP has/had a different approach. They bought used gear for destruction. Evil, but less evil than SRS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
Hi, HP sels (sold?) refurbishes instruments also. Henk Op 17 feb 2011, om 22:28 heeft li...@lazygranch.com het volgende geschreven: I've worked for Fortune 100 companies (let alone the top 500) and start-ups. They both often buy used gear. Even if the gear breaks and needs repairs, there are accounting reasons why buying used makes sense. (Repairs are expensed. Bean counters like that.) Thus to screw anyone that buys used is a poor business practice. HP has/had a different approach. They bought used gear for destruction. Evil, but less evil than SRS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
Hi Back a while Motorola bought up all the used two way gear they could via the trade in process. Every single piece of it went to the crusher, no exceptions for anybody. Very much in warranty or 20 years old, to the crusher it went. The practice made them few friends, but it apparently made business sense. I have no idea if they still do the crusher thing today or not. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of li...@lazygranch.com Sent: Thursday, February 17, 2011 4:28 PM To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SRS PRS10 problem I've worked for Fortune 100 companies (let alone the top 500) and start-ups. They both often buy used gear. Even if the gear breaks and needs repairs, there are accounting reasons why buying used makes sense. (Repairs are expensed. Bean counters like that.) Thus to screw anyone that buys used is a poor business practice. HP has/had a different approach. They bought used gear for destruction. Evil, but less evil than SRS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
I would just like to point out that SRS is one of the few companies who still provide complete manuals with parts lists and circuit diagrams (although circuits are only in the paper manuals, not the pdfs). Regards, Laurence Motteram -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Friday, 18 February 2011 8:11 AM To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SRS PRS10 problem I've had such blowoffs from SRS, simply asking for a schematic of an old power supply. Uncooperative and unhelpful is a total understatement. I will never buy any of their stuff again. I simply don't care if it is the best in the world (which it is probably not the case), if the documentation and other minimal support is not available, they are simply a company not worth dealing with. Even if I got it free, it's still not worth half the price. YMMV, -John = I wanted to say those customers who bought them new directly from them While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket. What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant. They do not want to exert control on who owns it later, but they exert control on what they do with their spares. Its a fact of life. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 18:26:41 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
On 02/17/2011 10:55 PM, Laurence Motteram wrote: I would just like to point out that SRS is one of the few companies who still provide complete manuals with parts lists and circuit diagrams (although circuits are only in the paper manuals, not the pdfs). They can actually deliver paper manuals... ponder a bit on that one... Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
Not unless you are the original purchaser, and can prove it. Contrast to HP. -John == I would just like to point out that SRS is one of the few companies who still provide complete manuals with parts lists and circuit diagrams (although circuits are only in the paper manuals, not the pdfs). Regards, Laurence Motteram -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Friday, 18 February 2011 8:11 AM To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SRS PRS10 problem I've had such blowoffs from SRS, simply asking for a schematic of an old power supply. Uncooperative and unhelpful is a total understatement. I will never buy any of their stuff again. I simply don't care if it is the best in the world (which it is probably not the case), if the documentation and other minimal support is not available, they are simply a company not worth dealing with. Even if I got it free, it's still not worth half the price. YMMV, -John = I wanted to say those customers who bought them new directly from them While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket. What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant. They do not want to exert control on who owns it later, but they exert control on what they do with their spares. Its a fact of life. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 18:26:41 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
li...@rtty.us said: The key item here is that the system is going to work via amateur radio here in the US. The FCC only lets you use three very specific PN sequences. The three are called out explicitly in the rules. The requirement that they not be reset while transmitting except by feedback is also called out explicitly in the rules. So no fancy stuff with multiple spreaders and the like. Thanks, but I'm having trouble understanding that. The problem is not be reset while transmitting except by feedback. I usually use reset to mean set the system to a specific state no matter what the current state. I think they are trying to say you can't use something like a PPS signal to reset the LFSR. If so, I would have said something like can't be reset. The next state can only be influnced by feedback. (Which also rules out the self-synchronizer type approaches which use the data bit rather than the LFSR output.) Are there any constraints on picking the initial state? (There has to be some time when the transmitter starts.) Can I send packets? Can I start each packet on a second boundary (and not reset if it goes over 1 second)? What do you call a clump of voice when something like a PTT is used? There's a much easier way to do it and keep everybody in sync. GPS gives you time of day along with the 1 pps signal. You agree that at this or that time, everybody starts in sync. It's just time math to figure out where you should be at any 1 pps point. If you aren't where you are supposed to be, you take action. That makes sense to me. I think you have to figure out what to do if the transmission crosses midnight. You can shut down and start over, or just keep going. In the latter case, you have to agree (out of band) which day you started in, but that only matters if you start near midnight. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SRS PRS10 problem
Better yet, HP has a ftp site with old manuals. HP (Agilent) isn't what it used to be, but I suspect it has its share old timers that at least try to keep the old HP spirit alive. -Original Message- From: J. Forster j...@quik.com Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 14:29:02 To: Laurence Motteramlmotte...@scientific-devices.com.au Reply-To: j...@quik.com, Discussion of precise time and frequency measurement time-nuts@febo.com Cc: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem Not unless you are the original purchaser, and can prove it. Contrast to HP. -John == I would just like to point out that SRS is one of the few companies who still provide complete manuals with parts lists and circuit diagrams (although circuits are only in the paper manuals, not the pdfs). Regards, Laurence Motteram -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Friday, 18 February 2011 8:11 AM To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SRS PRS10 problem I've had such blowoffs from SRS, simply asking for a schematic of an old power supply. Uncooperative and unhelpful is a total understatement. I will never buy any of their stuff again. I simply don't care if it is the best in the world (which it is probably not the case), if the documentation and other minimal support is not available, they are simply a company not worth dealing with. Even if I got it free, it's still not worth half the price. YMMV, -John = I wanted to say those customers who bought them new directly from them While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket. What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant. They do not want to exert control on who owns it later, but they exert control on what they do with their spares. Its a fact of life. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Thu, 17 Feb 2011 18:26:41 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] SRS PRS10 problem On 02/17/2011 12:23 PM, shali...@gmail.com wrote: It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price. Full price? Someone payed full price for it originally. The notion that can have control over who owns it later is strange and not relevant. Sending it to them for repairs may be possible thought. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
jleik...@leikhim.com said: 3) If I block the 1 PPS during PTT, and the receiving end asserts 1 PPS reset, will synch be lost? If not how effective will the freewheeling be during a 30 second exchange with 10 MHz GPS derived clock reduced to 20 hops/ second? The receiver has to do the same dance as the transmitter. (Maybe delayed a bit.) If not, you will be listening on the wrong frequency. Can you use something like a carrier detect to suppress the reset on the receive end? (Which might mean that you don't want to start near the end of a second.) How long you can freewheel depends upon how closely the clocks are synchronized. With a good GPSDO and good antenna, both 10 MHz clocks are going to track within a cycle long term. (that's months, not just seconds) If your antenna isn't good enough, you have to figure out what happens when it recovers from holdover. Does it slew the clock to catch up, preserving the cycle count, or does it jump to the correct frequency and add/delete a few cycles before the next PPS? Holdover specs for GPSDOs are on the scale of a few/10 microseconds per day, so even if one end goes into holdover for an hour, you won't be off much relative to the time-of-flight delays. But maybe you are using an inexpensive GPS receiver rather than a GPSDO. How good is your 10MHz clock? 30 seconds at 1 ppm difference is 30 microseconds. I picked 1 ppm because the math was simple and it's a reasonable ballpark for a target. Adjust for your setup. 4) 20 hops per second is a 50 ms chip. Two radios 50 miles apart would be 270 us delayed. I don't think that should impair the analog FM. So don't envision needing any correlation adjustment. Comments? If you have a 10 MHz clock, it's easy to delay the PPS signal by 2700 clocks. If you are doing the receiver in software, it may be reasonable to automatically fine tune the delay. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
Stan; Here is a source for the necessary tools: http://www.ofrei.com/page557.html Note that they are not inexpensive; something to factor in when you consider the overall cost of maintenance. If it really has been 20 years, there is every possibility that the battery has leaked, in which case the repair will not be trivial. Tom Frank On Feb 15, 2011, at 2:43 PM, Stan, W1LE wrote: Hello The Net: When I retired almost 2 decades ago, I put my wristwatch in a drawer and left it there. I was hoping to never have to use it again. Wishful thinking. Now I need it, but it does not work, battery is depleted. I need to open it up and replace the battery. Any idea how I get my Oysterquartz open. It does have a back cover, but is it a right handed or a left handed thread, and where can I find the best tool, without marring it ? Also, any idea what the battery part number is ? I should consider replacing the o-ring seal under the cover, any idea where to get one ? After I replace the battery, I hope to calibrate it, comparing it to my Trimble GPS/DO. Any help is appreciated. I had considered getting support from R-USA in NY, but previous support was horribly bad. Stan, W1LE Cape Cod FN41sr z ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On Thu, Feb 17, 2011 at 3:22 PM, Hal Murray hmur...@megapathdsl.net wrote: The receiver has to do the same dance as the transmitter. (Maybe delayed a bit.) If not, you will be listening on the wrong frequency. Can you use something like a carrier detect to suppress the reset on the receive end? (Which might mean that you don't want to start near the end of a second.) How long you can freewheel depends upon how closely the clocks are synchronized. I always thought the receiver's clock kept itself sync'd via a phase lock loop with the transmitter. So the transmitter timing could drift a bit off and the receiver would follow. This system also automatically takes care of propagation delays perfectly -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
On 2/17/11 2:46 PM, Hal Murray wrote: li...@rtty.us said: The key item here is that the system is going to work via amateur radio here in the US. The FCC only lets you use three very specific PN sequences. The three are called out explicitly in the rules. The requirement that they not be reset while transmitting except by feedback is also called out explicitly in the rules. So no fancy stuff with multiple spreaders and the like. Thanks, but I'm having trouble understanding that. The problem is not be reset while transmitting except by feedback. I usually use reset to mean set the system to a specific state no matter what the current state. you *could* call the FCC and ask them... Or, just build whatever, and wait for someone to complain, and say you misinterpreted the rules. Unless you're a jerk, I suspect that they won't fine you or anything else. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tool Needed to Access my Timer Battery
Think long and hard before you try a 2 or 3 pronged wrench on your 6 slotted back. It is almost impossible to not slip with the 2 prong wrench, and the 3 prong Jaxa style is not much better. The manufacturers sold little sheet metal wrenches that engaged all of the slots in the back, and as such are almost idiot proof. You fit the wrench to the back, set the watch face against your fingers, and squeeze the wrench to the back with your thumb. Then using your other hand rotate the wrench handle CCW to loosen. -Chuck Harris Thomas A Frank wrote: Stan; Here is a source for the necessary tools: http://www.ofrei.com/page557.html Note that they are not inexpensive; something to factor in when you consider the overall cost of maintenance. If it really has been 20 years, there is every possibility that the battery has leaked, in which case the repair will not be trivial. Tom Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PN sequence generation using GPS
jimlux wrote: you *could* call the FCC and ask them... Or, just build whatever, and wait for someone to complain, and say you misinterpreted the rules. Unless you're a jerk, I suspect that they won't fine you or anything else. Given the quality of the rank-and-file ham, and the fact that nobody, but hams really care what happens on the ham bands, who would ever know? I think you could run any form of SS you wanted to on the ham bands for the rest of your life, and as long as you were semi-competent about it (eg. didn't cause interference) you would remain undetected. -Chuck Harris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts!
I am curious what software and version you are running with these. On 2/17/2011 3:32 AM, David J Taylor wrote: David Taylor wrote: snip ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts!
From: jim s j...@jwsss.com Sent: Friday, February 18, 2011 7:12 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Garmin 18x, new firmware Ver 3.60, NOT recommended for Time Nuts! I am curious what software and version you are running with these. Personally, I'm running the 3.50 firmware, with the device connected to a Windows-7 PC running NTP - (ntpd 4.2.7p97). The software is configured to use just the PPS signal from the GPS, with the seconds being taken from other servers. One of those other servers is a FreeBSD system connected to a GPS 18 LVC mounted on the roof, which I trust! You can see the performance of both systems here: http://www.satsignal.eu/mrtg/performance_ntp.php The FreeBSD/GPS 18 LVC is PC Pixie, and the Windows-7/18x system is Stamsund - not a primary server but interesting to see just what Windows can do - it's mostly well within about fifty microseconds. The FreeBSD system is within about 10 microseconds. On both, you can see the effect of the heating switching on just before 06:00 UTC quite clearly! Cheers, David -- SatSignal software - quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
